Mapping Areas of Hard Bottom and Other Important Bottom Types: 
Outer Continental Shelf and Upper Continental Slope

OCS Study MMS 2005-067

The Minerals Management Service (MMS), Gulf of Mexico OCS Region, announces the availability of a new study report, Mapping Areas of Hard Bottom and Other Important Bottom Types: Outer Continental Shelf and Upper Continental Slope.

With the petroleum industry increasing operations along the northern Gulf of Mexico continental slope, it is important to locate and map areas of seafloor features, such as faults and areas of hard bottom that may be associated with sensitive biological communities. These features also constitute risks that may impact drilling, locating production platforms, laying pipelines, and related activities. There are a wide variety of descriptions and names coming from operators for similar features that often represent sensitive biological habitats. The results of this project will help in combining many of these terms into a focused set of categories. This end result will greatly benefit the MMS biological review process.

This project, conducted cooperatively through the Louisiana State University Coastal Marine Institute, was designed to convert existing seafloor maps compiled from high-resolution seismic profiles, side-scan sonar data, and bathymetry acquired in 182 OCS lease blocks to MMS-approved GIS format for use in geohazards evaluations. Six mapping categories were used: (1) undisturbed seafloor, (2) seafloor erosion, (3) hard-bottom areas (carbonate banks, bioherms, hardgrounds, and outcrops), (4) faults, (5) acoustic wipeout zones, and (6) mass movement features. In addition to converting existing maps, mapping of new 3-D seismic surface amplitude data filled many of the gaps in the high-resolution acoustic datasets. This project produced a set of seafloor maps from five mapping areas that can be used for planning activities in the OCS region of the northern Gulf of Mexico from the shelf edge to a depth of 1,000 m.

This report is available only in compact disc format from the Minerals Management Service, Gulf of Mexico OCS Region, at a charge of $15.00, by referencing OCS Study MMS 2005-067. The report may be downloaded from the MMS website through the Environmental Studies Program Information System (ESPIS). You will be able to obtain this report also from the National Technical Information Service in the near future. Here are the addresses. You may also inspect copies at selected Federal Depository Libraries.